Spinal distractor, compressor, and rod engaging system and method

ABSTRACT

Apparatus and methods for distracting or compressing distance between a first and second honey structure and for engaging a connecting element.

RELATED APPLICATIONS

This application is a continuation of co-pending U.S. patent applicationSer. No. 11/604,134, entitled “Spinal Distractor, Compressor, and RodEngaging System and Method,” filed Nov. 24, 2006, which claims thebenefit of priority to U.S. Provisional Patent Application Ser. No.60/739,268, filed Nov. 23, 2005. Priority of the aforementioned filingdates is hereby claimed and the entire disclosures of which are herebyincorporated by reference.

BACKGROUND

The invention relates generally to apparatus and methods for distractingor compressing the distance between a first and second boney structure.

It is desirable to enable a user to distract or compress the distancebetween a first and second boney structure. The present inventionprovides such a system and method.

SUMMARY OF THE INVENTION

The present invention includes apparatus and methods for controllablydistracting or compressing the distance between a first and second boneystructure via a connecting element.

BRIEF DESCRIPTION OF THE DRAWINGS

The features, objects, and advantages of the present invention willbecome more apparent from the detailed description set forth below whentaken in conjunction with the drawings in which like referencecharacters identify correspondingly throughout and wherein:

FIG. 1A is an isometric diagram of a compressor and distracter apparatuscoupled to a connecting element according to various embodiments;

FIG. 1B is a side, partial sectional diagram of a compressor anddistracter apparatus coupled to a connecting element according tovarious embodiments;

FIG. 1C is a top diagram of a compressor and distracter apparatuscoupled to a connecting element according to various embodiments;

FIG. 1D is a side, sectional diagram of a compressor and distracterapparatus coupled to a connecting element according to variousembodiments;

FIG. 1E is an exploded diagram of a compressor and distracter apparatusand a connecting element according to various embodiments;

FIG. 1F is an exploded diagram of a section of a compressor anddistracter apparatus according to various embodiments;

FIG. 2A is a diagram of a compressor and distracter apparatus coupled toa connecting element employed to compress or distract the disc spacebetween two vertebra according to various embodiments;

FIG. 2B is a diagram of a connecting element and bony structureinterface system for engaging the connecting element to a bony structureaccording to various embodiments;

FIG. 2C is a diagram of a compressor and distracter apparatus coupled toa connecting element and a bony structure interface system to distractthe bony structure relative to another structure according to variousembodiments;

FIG. 2D is a diagram of a compressor and distracter apparatus coupled toa connecting element and a bony structure interface system to compressthe bony structure relative to another structure according to variousembodiments;

FIG. 2E is a horizontal view of two connecting elements coupled torespective bony structure interface systems, the systems coupled to abony structure according to various embodiments; and

FIG. 2F is a sagittal view of a connecting element coupled to a firstand a second bony structure interface system, the first system coupledto a first bony structure and the second system coupled to the secondbony structure according to various embodiments.

DETAILED DESCRIPTION

Throughout this description, embodiments and variations are describedfor the purpose of illustrating uses and implementations of theinvention. The illustrative description should be understood aspresenting examples of the invention, rather than as limiting the scopeof the invention.

FIG. 1A is an isometric diagram of a compressor and distracter apparatus100 coupled to a connecting element 120 according to variousembodiments. The apparatus 100 includes a ratchet body or base 104,ratchet mechanism 117, ratchet actuator handle 106, ratchet directionselector 102, slidable hook 105, and hook slide recess and connectingelement holder 126. The hook slide 105 is coupled to the ratchetmechanism 117 where the slide 105 moves relative to the connectingelement holder 126. The slide 105 may move toward or away from theconnecting element 126 as a function of the ratchet direction selection102. In operation, the connecting element 120 distal end 123 may befixably coupled to a first bony structure (12 in FIG. 2A). The hookslide catch 125 may be physically coupled to a second bony structure (14in FIG. 2A). As the ratchet mechanism 117 is operated by handle 106 thesecond bony structure 14 may be compressed toward or distracted away thefirst bony structure 12. Due the ratchet mechanism 117, the compressionor distraction is controllably performed in discrete increments based onthe direction 102 and handle actuations 106.

The connecting element holder 126 may have a curvature radius, R1. Theconnecting element 120 may a curvature radius, R2. In embodiment R1 maybe similar to R2 to enable smooth compression or distraction between twobony structures 12, 14. Further, movement between the bony structures12, 14 may follow a curvature radius, R3 where R1 and R2 are similar toR3. In spinal applications R3 may be approximately equal to the lordosisbetween a first vertebra 12 and a second vertebra 14. FIG. 1B is a side,partial sectional diagram of the compressor and distracter apparatus 100coupled to a connecting element 120 according to various embodiments.The apparatus 100 includes a master pin 109 and main ratchet gear 101.The master pin 109 is couples the direction selector 102 to the ratchetmechanism 117. The main ratchet gear 101 have a fixed number of gearshaving a fixed tooth shape and size. The gear 101 is coupled toreciprocal teeth in the hook slide (124 in FIGS. 1D and 1E).Accordingly, when the ratchet mechanism 117 is actuated (via handle106), the hook slide 105 is moved a fixed, predetermined distance,permitting an apparatus 100 user to controllably distract or compressthe space or distance between two bony structures 12, 14.

FIG. 1C is a top diagram of a compressor and distracter apparatus 100coupled to a connecting element 120 according to various embodiments.The apparatus 100 may include a connecting element connector 121. Theconnecting element connector 121 may include a compressible collet thatmay be inserted into a connecting element 120 recess (122 in FIG. 1E).In an embodiment after the collet 121 is inserted into the connectingelement 120 recess 122, a locking pin (109 in FIG. 1E) may be insertedinto the collet 121 via the locking pin 109 actuator 128 (FIG. 1C). Thelocking pin 109 insertion may fixably expand the collet 121 within theconnecting element 120 recess 122 and prevent separation of theconnecting element 120 from the holder 126. In an embodiment theconnecting element 120 is a cylindrical rod that is substantiallyincompressible along its longitudinal axis. The connecting element 120may be any element 120 may span between two bony structures and asubstantially incompressible longitudinal axis. The connecting element120 may include a dynamic connector where the dynamic connector may bemade substantially incompressible along its longitudinal axis duringinsertion or implantation.

FIG. 1D is a side, sectional diagram of the compressor and distracterapparatus 100 coupled to a connecting element 120 according to variousembodiments. As shown in FIG. 1D the connecting element holder 126includes a sleeve for the hook slide 105. The hook slide 105 includes aplurality of teeth 124 at is proximal end. The teeth 124 are configuredto mate with the ratchet mechanism 117 main ratchet gears 101. When theratchet mechanism 117 is actuated via the handle 106 the hook slide 105is translated with the connecting element holder 126 so the hook slide105 catch 125 is moved relative to the fixed connecting element coupler(collet in an embodiment) 121. In an embodiment a first bony structureis fixably coupled to connecting element 120 distal end 123. A secondbony structure may be fixably coupled to another apparatus that isreleasably couplable to the hook slide 105 catch 125. The apparatus 100may then be actuated to translate the hook slide 105 relative thecoupled connecting element 120. Accordingly the second bony structure 14may be compressed toward or distracted away from the first bonystructure 12. In an embodiment the first and the second bony structuremay be single anatomical bony structure that has been separated such aslong bone fracture.

FIG. 1E is an exploded diagram of the compressor and distracterapparatus 100 and a connecting element 120 according to variousembodiments. FIG. 1F is an exploded diagram of a section of the ratchetmechanism 117 of the compressor and distracter apparatus 100 accordingto various embodiments. The apparatus 100 may include a ratchethousing/handle 104, director selector 102, main ratchet gear 101, pinadvancer 103, hook slide 105, ratchet actuator 106, hook slide cover107, lee spring 108, master pin 109, ball spring plunger 110, screw 111,lee spring 112, ratchet lock pin 113, ratchet lock pin 114, block pinadvancer 115, pin advancer 116, ratchet mechanism 117, screws 118,connecting element locking pin 119, connecting element coupler (collet)121, hook slide gear 124, hook slide recess/connecting element holder126, slide path 127, and locking pin control 128. As can be shown inFIGS. 1E and 1F the apparatus 100 enables a user to incrementallytranslate the hook slide 105 relative to the hook sliderecess/connecting element holder 126.

FIG. 2A is a diagram of a compressor and distracter apparatus 100coupled to a connecting element 120 employed to compress or distract thedisc space 13 between two vertebra 12, 14 of a spine 10 according tovarious embodiments. The spine 10 may include a plurality of vertebra12, 14 covered by skin 16. The connecting element 120 may be fixablycoupled to the first vertebra 12 via a bone connecting element (30 inFIG. 2B). The hook slide 105 may be coupled to the second vertebra 14via a bone connecting element 30 and connecting cannula 22B. Aconnecting cannula 22A may be coupled to first vertebra 12 via the boneconnecting element. Depending on the direction selection 102, actuationof handle 106 may distract the second vertebra 14 away from the firstvertebra 12 (FIG. 2C) or may compress the second vertebra 14 toward thefirst vertebra 12 (FIG. 2D).

FIG. 2B is a diagram of a connecting element 120 and bony structurecoupling system 200 for engaging the connecting element to a bonystructure according to various embodiments. The bony structure couplingsystem 200 may include a bone screw 30 coupled to a connecting element120 receiver 32 via a pin 38, a connecting element engaging saddle 34rotatably coupled to a receiver locking element 36, a locking elementdriver 40, and a cannula couplable to the receiver 32. The lockingelement driver 40 may be releasably coupled to the receiver lockingelement 36. The cannula 22 may include a cannula slot 24 that the hookslide catch 125 of the hook slide 105 may releasably engage.

FIG. 2C is a diagram of the compressor and distracter apparatus 100coupled to a connecting element 120 and a bony structure coupling system200 to distract a bony structure coupled to the system 200 relative toanother bony structure fixably coupled to the connecting element 120according to various embodiments. As shown in FIG. 2C as the hook slideis incrementally slide away from the connecting element 120 (forcevector 130), the system 200 is also distracted away from the connectingelement 120. FIG. 2D is a diagram of the compressor and distracterapparatus 100 coupled to a connecting element 120 and a bony structurecoupling system 200 to compress a bony structure coupled to the system200 toward another bony structure fixably coupled to the connectingelement 120 according to various embodiments. As shown in FIG. 2D as thehook slide is incrementally slide toward the connecting element 120(force vectors 130), the system 200 is also compressed toward theconnecting element 120.

FIG. 2E is a horizontal view of two connecting elements coupled torespective bony structure system 200, the systems coupled to a bonystructure 14 according to various embodiments. In FIG. 2E a bone screw30 in placed on a left and a right pedicle of a vertebra 14. Bone dowels42 may also be placed in a facet joints. FIG. 2F is a sagittal view of aconnecting element 120 coupled to a first and a second bony structurecoupling system 200. The first system 200 may be coupled to a first bonystructure 14 and the second system 200 may be coupled to the second bonystructure 12 according to various embodiments. The compressor anddistracter apparatus 100 may be used to distract or compress the discspace 13.

While this invention has been described in terms of a best mode forachieving the objectives of the invention, it will be appreciated bythose skilled in the art that variations may be accomplished in view ofthese teachings without deviating from the spirit or scope of thepresent invention.

1. A device for engaging a bony structure connecting rod having a recesspositioned at a proximal end, the device comprising: an elongated arm;and a collet on a distal end of the elongated arm, the collet configuredto be collapsed to a first outer diameter for insertion within therecess of the connecting rod and expanded to a second outer diameterwithin the recess of the connecting rod such that the collet isprevented from separating from the connecting rod.
 2. A device of claim1, wherein the collet comprises a bushing and a flexible sectionincluding a plurality of flexible arms surrounding a central bore.
 3. Adevice of claim 2, wherein the distal end of the elongated arm iscoupled to the bushing of the collet.
 4. The device of claim 2, furthercomprising a locking pin configured to extend through the central boreto expand the plurality of flexible arms away from one another andmaintain the flexible section in the expanded second outer diameter. 5.The device of claim 4, wherein the locking pin is sized to prevent theflexible section of the collet from collapsing from the second outerdiameter and maintain the collet in a locked association with theconnecting rod.
 6. The device of claim 5, wherein the locking pin wheninserted through the central bore of the collet couples the connectingrod to the elongated arm.
 7. The device of claim 6, wherein theelongated arm is coupled to a handle at a proximal end region.
 8. Thedevice of claim 6, further comprising a locking pin advancer having aproximal end coupled to the handle and a distal end coupled to thelocking pin, wherein the locking pin advancer extends through an innerchannel in the elongate arm.
 9. The device of claim 8, furthercomprising a locking pin actuator that slidably controls the locking pinadvancer through the inner channel.